RM Sotheby's
Mid-level M&A bankers earned a median bonus of £80,000 ($99,516) in 2016, according to the survey.
While that is more than what colleagues make elsewhere in investment banking, it is still 20% less than last year.
M&A has been exceptionally busy in 2016, with record deal volumes split between a handful of large investment banks and advisory boutiques.
October was a bumper month, with shareholder approval for the £79 billion tie-up between brewery giants SABMiller and Anheuser-Busch InBev as well as the merger between asset managers Janus Capital and London-based Henderson Group.
Alice Leguay, co-founder and COO at Emolument said: "Over the last couple of years we have seen a huge polarisation in bonuses especially in mergers and acquisition. This applies to specific banks: those who have access to the high flow of deals and fees, versus the non-performing banks in M&A."
Trading bonuses were stable at £65,000 while bonuses for bankers in origination, which involves bringing corporate debt and equity to the market, crumbled 30%.
Here is the chart:
Emolument